Stator Functions 1 Blades 2 Stator held - fluid flow re-directed 3 Stator rotates freely 4 Roller clutch 5 Converter at coupling speed 6 Fluid flow from turbine 7 Converter multiplying 8 Fluid flow from impeller 9 Drive from engine 10 Impeller 11 Stator 12 Turbine 13 Output to transmission Refer to the 'Stator Functions' illustration Fluid emitted from the impeller acts on the turbine. If the turbine is rotating at a slower speed than the fluid from the impeller, the fluid will be deflected by the turbine blades in the path 'A'. The fluid is directed at and deflected by the stator blades from path 'B' to path 'C'. This ensures that the fluid is directed back to the pump in the optimum direction. In this condition the roller clutch is engaged and the force of the fluid on the stator blades assists the engine in rotating the impeller As the rotational speed of the engine and therefore the turbine increases, the direction of the fluid leaving the turbine changes to path 'D'. The fluid is now directed from the turbine to the opposite side of the stator blades, rotating the stator in the opposite direction. To prevent the stator from resisting the smooth flow of the fluid from the turbine, the roller clutch releases, allowing the stator to rotate freely on it shaft. When the stator becomes inactive, the torque converter no longer multiples the engine torque. When the torque converter reaches this operational condition it ceases to multiply the engine torque and acts solely as a fluid coupling, with the impeller and the turbine rotating at approximately the same speed.
AUTOMATIC TRANSMISSION – GM LE DESCRIPTION AND OPERATION